The present invention relates to a high-pressure centrifugal blower having blades fitted to the back plate of its impeller, the blades extending from the periphery of the impeller over some distance radially inwards. When the impeller of the blower rotates, a pressure difference is created in the blower case between its inflow side and its outflow side. This pressure difference produces an axial load on the blower bearings, the magnitude of the load being the area of the blower suction inlet multiplied by the pressure difference between the inlet and the outlet.
In low-pressure blowers this load is not significant, owing to the low pressure, but with increased pressure the significance of this load increases, and in high-pressure blowers the axial load is a factor decisive in dimensioning.